The combination of cyclophosphamide plus interferon beta as rescue therapy could be used to treat relapsing–remitting multiple sclerosis patients

The aim of the present study was to evaluate the efficacy of the combination of cyclophosphamide (CTX) and interferon beta (IFN β) in a group of relapsing remitting (RR) multiple sclerosis (MS) patients who experienced treatment failure during IFN β therapy. It is the general experience that immunomodulatory agents (IMA) are only partially effective in RR patients. Recent data on the efficacy of immunosuppressive therapies for these patients are encouraging. The anti–inflammatory and immunosuppressive effects of CTX have been utilized to treat selected cases of multiple sclerosis with a progressive and worsening course as rescue therapy. Thirty RR MS patients with clinically defined MS who experienced treatment failure during IFN β therapy (2 or more relapses per year or 1.5 EDSS point worsening in one year) were enrolled in the study and treated with CTX iv pulse therapy added to IFN β and followed up for 24 months. As primary endpoints we evaluated the yearly relapse rate. We also evaluated the percentage of patients free of relapses and of EDSS variations. We analysed the results at one year before entry (T0: IFN β alone), 12 (T1) and 24 (T2) months after entry. Brain MRI was performed at T0, at T1 and T2. The 30 RR patients who had experienced a high number of relapses (r r =1.4) at T0 showed a significant improvement in yearly relapse rate (rr = 0.4) at T1 and a further improvement (rr = 0.17) at T2 (p < 0.001). The percentage of patients free of relapse was 70% at T2 (p < 0.0001). EDSS score changed from 2.6±1.23 at T0 to 2.2 ± 1.5 at T2, showing only a trend of improvement.No significant variation of MRI lesion load and no severe adverse events were recorded during the study. These data showed that the combination of CTX plus IFN β halted the progression of disease in active and deteriorating MS patients suggesting the necessity of RCTs to test the efficacy of this combination therapy in active RRMS patients or in patients who experienced treatment failure in response to disease modifying drugs (DMDs).